Cooperative multi-agent based distributed power sharing strategy in low voltage microgrids

In this paper, a cooperative multi-agent system (MAS) is presented for proportional power sharing in microgrids through a coupling of distributed control and communication techniques. Due to natural intermittency of wind and solar along with the limited capacity of battery storages, it is essential to manage optimal power sharing to ensure the supply-demand balance as well as minimizing the generation cost to achieve an economical operation of the system. In order to optimally utilize the battery storage capacity, this paper emphasizes the proportional power sharing from power electronic inverter interfaced battery storage units. A benchmark low voltage (LV) microgrid is considered and the MAS framework is developed through the well-known graph theory to enable a communication link among the controllable battery inverters where each agent is considered to be embedded to the battery inverter control unit. An optimal linear quadratic regulator (LQR) is designed within a distributed control context to regulate the power injections into the system from the battery inverters. Simulations are justified under practical circumstances of wind and solar intermittency, and communication constraints where the accuracy of power sharing is achieved through consensus algorithm via information exchange among the control agents.